Metallic bundling devices, such as cable ties, which incorporate locking devices or mechanisms, such as balls or roller pins, have been used for bundling a great variety of items, such as bales of cotton, since the Nineteenth Century. However, such devices were not “positive” locking; that is, such devices could not adjust for the situation in which gravity would prevent or urge the ball out of locking engagement with the strap, resulting in the release of the cable ties, and, consequently, the items intended to be restrained.
U.S. Pat. No. 4,399,592 to Chopp, Jr., et al. (“the '592 Patent”) addressed this problem by teaching the addition of a raised portion or protuberance for deflecting the threaded strap away from the floor, as the threaded strap exits the locking head. This deflection ensures that the locking device is in continuous engagement with the threaded strap, regardless of the position of the locking device or the orientation of the locking head. The '592 Patent, which is assigned to the same Assignee as the present invention, is hereby incorporated by reference in its entirety.
Although the '592 Patent provided a solution to the positive locking problem of the prior art, it nevertheless was necessary to develop a cable tie having an improved tensile strength, which could result in a quicker lockup and, ultimately, a tighter bundle. U.S. Pat. No. 6,668,427 to Bulanda, et al. (“the '427 Patent”) addressed this problem by teaching the use of a steeper incline on the inside of the locking head. The steeper incline allows the locking device to more quickly be positioned into a locking position. This quicker lockup then provides for a tighter contact and fit between the locking device and the strap. The '427 Patent, which is also assigned to the same Assignee as the present invention, is hereby incorporated by reference in its entirety.
Although the '427 Patent provided a solution to the need for a quicker lockup and a tighter bundle, there nevertheless existed a need for a cable tie that could be used to provide an even stronger bond between the locking device and the strap. HELLERMANNTYTON attempted to develop a metallic bundling device incorporating a multiple locking device system, such as embodied in Part Nos. MBT20XH and MBTX20HC. However, the device fails to fully provide for a strong bond between the locking devices and the strap. Among other aspects, the device does not allow for easy access to the locking devices, thus there is little or no retained tension. Moreover, the device has a lower loop tensile strength than the multiple ball metal locking tie of the present invention. Accordingly, the device does not fully maximize the potential of a multiple locking device system.
It would thus be desirable to provide a multiple ball cable tie having increased tensile strength.
It would also be desirable to provide a multiple ball cable tie having increased retained tension.